A client in cardiovascular collapse requires pharmacologic interventions. What route of administration is most likely appropriate?

Correct Answer: A

Rationale: The correct answer is A: Intravenous. In cardiovascular collapse, immediate action is crucial. Intravenous administration ensures rapid delivery of medications directly into the bloodstream, achieving quick onset of action. Oral route is too slow, rectal route may be unreliable, and topical route is not suitable for immediate systemic effects. Intravenous route is the most appropriate in this critical situation.

Correct Answer: B

Rationale: The correct answer is B: Biological half-life. The biological half-life of a drug determines the duration of action and how frequently it needs to be administered. Cephalexin has a short half-life of around 1 hour, so it needs to be given every 8 hours to maintain therapeutic levels. Explanation for why the other choices are incorrect: A: Propensity to go to the target receptor - While this is important for drug efficacy, it does not dictate the dosing frequency. C: Pharmacodynamics - While pharmacodynamics refers to how a drug works in the body, it does not directly impact the dosing interval. D: Safety and side effects - While safety and side effects are important considerations, they do not determine the dosing frequency.

Correct Answer: D

Rationale: The correct answer is D because peak levels indicate the highest concentration of the drug in the bloodstream after administration and trough levels indicate the lowest concentration before the next dose. By measuring both, healthcare providers can ensure the drug is within the therapeutic range for efficacy and safety. Choice A is incorrect as a wide therapeutic range does not negate the need for monitoring levels. Choice B is incorrect as the duration of drug administration does not determine the need for level monitoring. Choice C is incorrect as receptor saturation does not directly relate to the need for peak and trough level monitoring.

Correct Answer: B

Rationale: Step 1: Receptor antagonists block the action of agonist drugs by binding to the receptors. Step 2: Beta blockers are receptor antagonists that block beta-adrenergic receptors. Step 3: Abrupt discontinuation of beta blockers can lead to an exaggerated response due to unopposed stimulation of beta receptors. Step 4: This can cause rebound effects like increased heart rate and blood pressure. Step 5: Therefore, an exaggerated response if abruptly discontinued is the correct answer. Summary: A: Down-regulation of drug receptors is incorrect because antagonists blocking receptors do not lead to down-regulation. C: Partial blockade of agonist drug effects is incorrect as antagonists fully block agonist effects. D: Exaggerated response to competitive drug agonists is incorrect as antagonists reduce the response to agonists.

Correct Answer: B

Rationale: The correct answer is B: Greater than the sum of the effects of each drug individually. When two drugs have a synergistic effect, they enhance each other's actions, leading to a combined effect that is more potent than what would be expected by simply adding their individual effects. This occurs due to the drugs targeting different pathways or mechanisms, resulting in increased efficacy. In contrast, option A (The sum of the effects of each drug individually) is incorrect because synergy implies an interaction beyond mere addition. Option C (Less than the effect of each drug individually) is incorrect as synergy typically leads to enhanced effects. Option D (Not predictable) is incorrect because synergy can be anticipated based on the mechanisms of action of the drugs involved.